Firth Ecopave system installation guide

Transcription

1 Firth Ecopave system installation guide CBI 8211, 8231 November 2011 EnviroPave PorousPave The Firth EcoPave System is a complete paving system that will help to maintain the natural water balance as part of a property development. FlowPave Gobi Block Grass Paver

2 TABLE OF CONTENTS 1. Introduction Terminology System Choices Table 1 Application Unit type Choice Table Installation Cross section drawing EnviroPave 50mm Installation Cross section drawing PorousPave 60& 80mm Installation Cross section drawing FlowPave Installation Cross section drawing Grass Paver Installation Cross section drawing Gobi Block Impermeable Sub-Grade Pavement Storage Tank Sub-Base Method 6 2. Construction Materials Base Course Pervious Concrete Enviromix Drainage Aggregate Winstones WAP12 Table Bedding Material Bedding Sand Bedding Chip Winstones WAPP7 Table Jointing Material Jointing Sand Jointing Chip Winstones WAPP7 Table Characteristics Table 4 of Greywacke WAPP7 and WAPP Permeable Pavers Base course thickness and Filtercloth Classification Table Geotextile Geogrid 9 3. Planning and Preparation Installation Installation Surrounding/Covering Tree Root Zones More Information Frequently Asked Questions References 13 1

3 FIRTH ECOPAVE SYSTEM INSTALLATION GUIDE 1. Introduction This guide is for the installation of the Firth EcoPave System, a permeable, concrete paving system and should be read in conjunction with the Firth EcoPave System Brochure. This guide should be used in consultation with an engineer, architect or landscape architect in order to ensure compliance with council requirements and project conditions. Pavements should be designed in consultation with a qualified civil engineer and within the guidelines of NZS 3116:2002, with due consideration of the likely moisture sensitivity of the sub-grade and the need for filter fabrics. Normal GAP types of aggregate are not suitable as base course material and will lead to pavement failure if used. 1.1 Terminology Cross section of typical permeable pavement Bedding Layer Permeable pavers are bedded on 20mm layer of either sand or chip depending on the type of permeable paver used. Base course The structural drainage layer underneath the bedding layer, which can be either drainage aggregate or a no- fines concrete. This layer is also referred to as sub-base or storage medium as it can act as a storage tank once the storm water run off has dissipated into it. Sub-grade The undisturbed soil at the bottom of the pavement system. The strength of this influences the thickness of structural support layer of the base course. Sub-surface drain A drainage system which allows water to enter it so it can be directed out of the base course. Assists with removing water in impermeable clay sub-grades and can be designed to reduce the stormwater peak flow. Filter cloth Normally a non-woven Geotextile which is a polypropylene fabric which allows water to pass through it and prevents the bedding sand from migrating into the sub-base drainage aggregates. Also assists in stopping contamination of the sub base drainage aggregates when surrounded by clay soil. 2

4 1.2 System Choices Table 1 - Application, Unit Type choice and indicative base course thickness Note: Base course thicknesses are indicative only and are provided to give an example of typical construction. This table does not replace the use of engineering advice. Base course Thickness and Filter Cloth Classification Loading Condition Sub Grade Classification (Soaked) Type of Paver Residential Pedestrian Patio / Pathway Weak CBR 5 100mm Medium CBR mm Strong CBR mm EnviroPave 50mm PorousPave 60mm Geotextile Filter Cloth Class C Class B Class A Grass Paver 80mm Residential Light Traffic Single Unit Residential Driveways Geotextile Filter Cloth 150mm Class D 125mm Class C 100mm Class B EnviroPave 50mm PorousPave 60mm PorousPave 80mm FlowPave 80mm Grass Paver 80mm* Gobi Block 100mm* Residential Light to Medium Traffic Multi Unit Residential Driveways Specific Design 150mm 125mm PorousPave 80mm FlowPave 80mm Geotextile Filter Cloth Public Footpath Low and High Impact Geotextile Filter Cloth 100mm Class D Class D 100mm Class C Class C 100mm Class B Commercial Grade EnviroPave 50mm PorousPave 60mm Notes: 1) For small jobs NZS3116:2002 suggests the following sub-grade assessment test which may be sufficient. Weather conditions can however significantly influence the test. The test should therefore be carried out under wet ground conditions: Weak - Walking leaves a strong foot imprint. Medium - Heel pressure leaves an imprint. Strong - No imprints. 2) For moisture sensitive soils (the soaked and unsoaked CBR s are significantly different i.e. clays). The thickness of the base course should be increased by at least 50mm above the values provided in the table above. 3) Where soils are known to be expansive (large volume change in wet and dry states), engineering advice should be sought. A solution sometimes adopted is to provide an impermeable liner above the expansive material. 4) Greater base course thickness than indicated above may sometimes be required for water storage or hydraulic requirements. 5) Specific design is required where soaked CBR is less than 5. However, a solution often used in very soft sub-grades is to provide a mm layer of GAP40 below the drainage base course with a biaxial geogrid at the interface between subgrade and GAP40. See installation guide for more detail. * Gobi and Grasspavers are suited to residential parking areas for light vehicles such as campervans, caravans and boats. To determine the on-site sub-grade CBR value use the Scala Penetrometer Test as per NZS 4402:1986 3

5 1.2.2 Installation Cross section drawing EnviroPave 50mm Installation Cross section drawing PorousPave 60mm & 80mm Installation Cross section drawing FlowPave 80mm 4

6 1.2.5 Installation Cross section drawing Grass Paver Installation Cross section drawing Gobi Block 1.3 Impermeable Sub-Grade pavement For impermeable sub-grades like Waitamata clays the water needs to be managed by facilitating the removal of the runoff water by means of sub-surface drains back into the storm water system. 5

7 1.4 Storage Tank Sub-Base Method By installing a heavy duty plastic tanking membrane around the sub-base you can create a storage tank of runoff water underneath your permeable pavers. With the installation of a cesspit and a pump this water can be pumped out and used to flush toilets or water the garden. 2. Construction Materials 2.1 Base Course Material [storage media] The base course material shall be either Firth EnviroMix concrete or Winstones drainage aggregate WAPP Firth EnviroMix [no fines] Concrete.19mm EnviroMix concrete will store approximately 250lt./m 3, or, when laid 100mm thick, it will store approximately 25lt./m² Winstones Sub-Base Drainage Aggregate WAPP mm Table 2 - WAPP12 grading envelope Sieve Size (mm) WAPP12 Upper Limit Lower Limit 19.0mm mm mm mm mm mm 0 10 WAPP12 will store approximately 400litres/m 3, or when laid 100mm thick, will store approximately 40litres/m 2. 6

8 Specific Requirements: The material shall produce less than 10% fines under a load of 120kN when tested in accordance with NZS 4407:1991 Test The material shall contain no deleterious material such as organic or clay material. The broken face content shall be not less than 70% by weight and have 2 or more broken faces when tested in accordance with NZS 4407:1991 Test Bedding Material The bedding material can either be sand or aggregate chip depending on which type of permeable paver is chosen. See cross-section drawings for specific types of pavers Bedding Sand The bedding sand shall comply with NZS3116:2002 Table 4 Sand category III residential, residential driveways and public footpaths. Table 4 - Grading limits for bedding sand BS sieve size Percentage by mass passing Sand category I Sand category II Sand category III 5.00 mm 90 to to to mm 75 to to to mm 55 to to to µm 35 to to to µm 10 to 45 5 to 48 5 to µm 0 to 10 0 to 15 0 to µm 0 to to 3 0 to 5 (1) Note: (1) For residential pedestrian applications a 0-10% range can be used. Copyright Standards New Zealand Content from NZS 3116:2002 has been reproduced with permission from Standards New Zealand under Copyright License For full details, please refer to NZS 3116:2002, available to purchase from the Standards New Zealand website. Specific Requirements: The material shall contain no deleterious materials such as clay or organic material, nor contain more than 2.5% of lightweight particles as determined by NZS 3111: Bedding Chip Winstones WAPP7 and shall comply with the following grading and requirements. Table 3 - WAPP7 grading envelope Sieve Size (mm) WAPP7 Upper Limit Lower Limit 19.0mm 13.2mm 9.5mm mm mm mm 3 0 7

9 Specific Requirements: The material shall produce less than 10% fines under a load of 120kN when tested in accordance with NZS 4407:1991 Test The material shall contain no deleterious material such as organic or clay material. The broken face content shall be not less than 70% by weight and have 2 or more broken faces when tested in accordance with NZS 4407:1991 Test Jointing material The jointing material can either be a sand or an aggregate chip depending on which type of permeable paver is chosen Jointing Sand The joint sand shall conform to NZS 3116:2002 Table 5 Other. Table 5 - Grading limits for joint sand Sieve size Roads and Industrial Pavements Per cent passing Other Per cent passing 2.36 mm mm µm µm µm µm Copyright Standards New Zealand Content from NZS 3116:2002 has been reproduced with permission from Standards New Zealand under Copyright License For full details, please refer to NZS 3116:2002, available to purchase from the Standards New Zealand website. Specific Requirements: The material shall contain no deleterious materials such as clay or organic material, nor contain more than 2.5% of lightweight particles as determined by NZS 3111: Jointing Chip WAPP7 2-7mm drainage chip This jointing chip is the same aggregate as the bedding chip in Section 2.2.2, Table 3. The FlowPave 80mm and the EnviroPave 50mm uses this jointing chip. The corners of the EnviroPave 50mm is filled with this aggregate. 8

10 2.4 Table 4 - Characteristics Table of Greywacke WAPP7 and WAPP12 Property Standard Test Method Result Source Production Other Solid Density NS4407:1991 Test t/m 3 Abrasion Resistance (Los Angeles Test) NS4407:1991 Test 3.12 ~11% Weathering Quality NZS3111:1986 Test 15 AA Crushing Resistance NZS3111:1986 Test Permeability Volume 2, Section 10.6 Method of soil laboratory testing by K.H. Head k = m/s Broken Face Content NZS4407:1991 Test % Cleaness Value NZS3111:1986 Test Maximum Dry Density NZS4402:1986 Test Minimum Dry Density NZS4402:1986 Test WAPP12~1.65 t/m 3 WAAP7~1.60 t/m 3 WAPP12~1.45 t/m 3 WAPP7~1.45 t/m 3 Total Voids % (From Maximum Dry Density Data) >40% 2.5 Permeable pavers Permeable pavers shall comply with NZS3116:2002 Table 1 for breaking loads, dimensional tolerance, abrasion and slip resistance. 2.6 Base course Thickness and Filter Cloth Classification See Table 1 in sect Note: Sub-grades weaker than a CBR of 5 will require specific design. 2.7 Geotextile Non woven Polypropylene Geotextile fabric type set out as in Table 1 in sect Geogrid For pavement construction using biaxial geogrids over very soft subgrade (CBR 3% or less) it is recommended not to use vibrating compaction equipment. This is to reduce the possibility of livening of the soft subgrade and pumping of soil particles up into the basecourse before sufficient interlock has been achieved with geogrid. If the subgrade is livened as a result of over-compaction and (or) excessive water, roading construction should be put on hold to allow constructed work to set up before proceeding with subsequent layers. The first layer thickness should be 150 to 200mm thick. Truck loads of sub-base shall be tipped into stockpiles on the subgrade and not tipped directly on geogrids. The sub-base stockpiles should be spread by mechanical plant such as loader with an opening bucket or excavator bucket. The first layer should be carefully static rolled with a small number of passes using a light roller to create a grid/aggregate interlock. If pavement was designed for multi layers of geogrids, all additional layers should be also carefully static rolled a small number of passes. If construction is taking place in wet conditions and pumping is likely, a layer of geotextile should be placed beneath layer of geogrid. Considering the fact that geogrids have square apertures they may be placed on the subgrade either parallel to the road centre line or in the transverse direction. The width of overlap between adjacent rolls is dependent upon grading and thickness of sub-base and the stiffness of the subgrade. The minimum overlap shall be 300mm and maximum shall be 600mm or as specified by the Engineer. Overlaps must be maintained during the filling operation. This is generally achieved by placing small heaps of fill locally over the overlaps ahead of the main filling operation. No traffic or site plant shall be permitted to travel on the geogrids prior to placing sub-base aggregate. Compaction of unbound materials for sub-base and road bases shall normally be carried out in accordance with specifications for sub-base aggregate. Compaction of other fills shall be carried out in accordance 9

11 with specifications for earthworks construction. Standard roading drainage practices should be followed, particularly maintaining the ground water level a minimum of 600mm below the sub-grade level. as With soft sub-grades an extra layer of GAP40 or GAP65 150mm-200mm needs to be laid on top off a suitable geogrid to provide a structural platform for the permeable base course to assist with the load capabilities. 3. Planning & Preparation Before commencing installation, assess the nature of the project. In particular, consider how the paving will be laid in conventional terms, and, how the EcoPave System will manage rain, stormwater & runoff. On large surfaces it may be necessary to get the system hydrologically engineered to ensure the pavement can manage the required run off capacity from a water management point of view. Ensure that each of the following is understood & completed prior to the actual start of the job: 3.1 Locate and mark the area to be paved. 3.2 Verify the location, type and elevations of edging around the perimeter. 3.3 Excavation depth will depend on which EcoPave System is being used (See table 1 sect 1.2.1). Excavate ensuring that the sub-base foundation is appropriate for the amount of traffic it will be subjected to. The required excavation depth for either the Detention or Infiltration system will need to be calculated based on a combination of Table 1 and the amount of water the system is expected to store (refer to section 2, for the storage capacity of the chosen base material i.e. Winstone s drainage aggregate or Firth s Enviromix no- Fines concrete). Ensure the sub-grade (soil) is compacted to the specified density and moisture content. Note! Compaction of the soil sub-grade should be to a minimum of 5% CBR for pedestrian areas and residential driveways, and a minimum of 10% CBR for vehicular areas. Stabilisation of the soil and/or base material may be necessary with 10

12 weak or saturated soils, or when subject to high wheel loads. Compaction will reduce the permeability of soils. These conditions may require the use of drains in open graded bases). On site sub-grade CBR can be determined by Scala Penetrometer Test as per NZS 4402: Once excavation is complete, ensure that the sub-grade is free from standing water, uniform and even. There should be no organic material or debris on the site prior to the start of the job. 3.5 Where necessary, it is acceptable to apply bedding sand immediately on top of the sub-grade [prior to applying the geotextile] in order to even out any undulations/holes on the surface of the sub-grade. 3.6 The site is now ready for installation. Note: A sloping site will have less storage capacity than a level site as water will resurface at the lowest point. This can be overcome by encouraging cross flow (through the installation of weirs) or concentrating storage capacity at the lowest point of the design. Alternatively, a drainage coil can be incorporated into the design allowing water to disperse to another drainage system. 4. Installation 4.1 Lay the geotextile on the bottom of the excavation, ensure that there is sufficient geotextile available to go up each side of the excavation and approximately 30cm onto the top of the sub base Note: The geotextile must encapsulate the storage medium on all sides. 4.2 Carefully install the sub-base (ie. Winstones WAPP12 drainage aggregate or Firth EnviroMix concrete) on top of the geotextile. Install enough aggregate/concrete to ensure the pavers will sit at the correct height once they have been installed on the bedding layer. Vibrating plate compactors must be used to consolidate the aggregate. Static or vibrating rollers are not effective. 4.3 Application of Blinding Layers (Where necessary) If the surface of the installed aggregate/enviromix is rough and displaying both low & high points even after compaction, in some situations it may be necessary to apply a blinding layer to the top of the storage media in order to obtain a smooth surface prior to installation of the top layer of geotextile. Depending on the material used for the sub-base, the blinding layer could be WAPP7 or Bedding Sand as stated in The application of a blinding layer will prevent the bridging of the geotextile across voids in the sub base. It will not affect the permeability of the system. 4.4 The elevation of the compacted surface should not deviate more than ±8mm over a 3m straightedge. 4.5 Lay geotextile filter fabric over the top of the base course and lap with fabric coming up the sides to completely encapsulate the base course material with an overlap of 200 mm. 4.6 Install bedding sand or WAPP7 chip & pavers, ensuring haunching or kerbing is adequate to retain the bedding sand. The pavement should be protected from contamination from surrounding construction and avoid getting clay and dirt into the system. Dirty run off into the permeable pavement will clog it and render it inoperable. 4.7 All Pavers shall be installed as per NZS 3116:2002. However, upon completing the laying of pavers, follow this procedure: 1. Compact paving without jointing sand (as per NZS 3116:2002). Spread jointing sand into joints and sweep all excess material off the surface. DO NOT compact the paving with sand on the surface (the sand will break down and partially fill the voids and reduce the permeability of the paving system). Compact paving for a second time. 2. A final top up of jointing sand can be achieved by washing sand into the joints. 4.8 Any contamination of the paving should be removed using low pressure water blasting followed by resanding of the joints. 11

13 4.9 All pavers within 1m of the laying face must be left fully compacted at the completion of each day The final surface elevations shall not deviate more than ±8mm under a 3m long straightedge The surface elevation of pavers shall be a minimum of 5mm above adjacent drainage inlets, concrete collars or channels Prior to first use, ensure that any residual sand is swept/washed off of the surface. 5. Installations Surrounding/Covering Tree Root Zones The Firth EcoPave System is, in some circumstances, suitable for installation immediately adjacent to trees & tree root zones. Permeable paving installed properly will contribute significantly to the long-term sustainability of the tree. Any installation that will cover a tree root zone should be designed in conjunction with an engineer. Please note the following specific requirements: 1. The tree root zone should not be excavated [ie. the roots should be preserved]. NOTE! THIS PERTAINS ONLY TO INSTALLATIONS SURROUNDING TREES AND DESIGNED TO SPECIFICALLY PRESERVE THE TREE ROOT ZONE. 2. Providing the following conditions can be met: The topsoil is not prone to settling/subsiding and The maximum weight of vehicles is limited [ie. residential light traffic/single unit residential driveways]. Then in some circumstances it is acceptable to install the EcoPave System on top of the existing top soil. However it is recommended that the advice of an engineer be sought. Whenever installing EcoPave paving on/around tree roots Firth EnviroMix should be used in lieu of a coarse, open graded material. This will be beneficial in that it will: Maintain permeability from the surface to the tree root zone. Reduce the need for compaction [which affects permeability]. Reduce the need for excavation of the root zone. Should there be any shrubs next to an installation, it is recommended that the likely effect of lime/high ph levels [caused by the EnviroMix Concrete] on adjacent flora be investigated prior to pouring EnviroMix. 6. More Information For more information on design and installation of the Firth EcoPave System, or the name and location of product suppliers and permeable paving installation contractors, please contact Firth Customer Services on or go to our website and work out your approximate quantities using our permeable pavement calculator. 7. Frequently Asked Questions Whats the difference between the Porous paver 80mm and the Flowpave 80mm paver? The Porous Paver is like a no-fines concrete made with a 7mm chip which allows runoff water to permeate through the actual paver itself. The Flowpave paver is a solid unit with enlarged spacer nibs (7mm) which widen the joints between the pavers to allow the runoff water to permeate through the joints. Whats the difference between the installation of the Porous pave 80mm and the Flowpave 80mm? The porous paver uses sand for both the bedding and jointing material. The Flowpave paver uses a chip for both the bedding and jointing material. Both pavers have either a suitable drainage aggregate or Enviromix no fines concrete sub base. 12

14 How does the drainage aggregate in the sub - base clean the run off water? Through a process called Cation Exchange Capacity (CEC). This is the tendency of media to attract/hold onto positively charged ions (cations). In terms of water quality treatment from stormwater runoff, a high CEC would indicate a good potential to absorb heavy metals or nutrients that might be carried in runoff. What kind of aggregates can I use for the sub base? Specifically designed drainage aggregates that are structurally sound when fully saturated/submerged with water. Normal GAP types of aggregate are not suitable and will lead to pavement failure. How long does it take before the system clogs up? Its difficult to be specific due to every location being different and dependant if it s located in the right position and how much sediment there is in the runoff. The location of where the permeable pavement is installed plays an important role with the sediment loading and hence life span of the system. Areas that will be subject to organic loading (leaves from trees) should be carefully considered together with a sweeping (without vacuum) regime. Other locations which will have a high clay content in the runoff should be avoided. Permeable pavements have a very high permeability and are approximately 10 fold the requirement to allow for sediment loading to achieve longevity. Research has shown that with some sediment loading and NO cleaning the Flowpave system will last many years (See Development and Assessment of a Permeable Paving System for Stormwater Quality Management by Navin Weeraratne, degree of Master of Engineering in Environmental Engineering, The University of Auckland August 2004). How can I test the permeability of my pavement system? One of the test methods is ASTM C 1701/C 1701M -09 Standard Test Method for Infiltration Rate of in Place Pervious Concrete is simple and easy to conduct in on site locations. 8. References Smith, David R. Permeable Interlocking Concrete Pavements, 2nd Edition. Interlocking Concrete Pavement Institute (ICPI) New Zealand Standards. Concrete Segmental Paving, NZS 3116:2002. Further information Permeable pavement performance for use in active roadways in Auckland, New Zealand by Elizabeth A. Fassman, PhD and Samuel David Blackbourn, ME Auckland University. EPA United States Environmental Protection Agency Surface Infiltarion Rates of Permeable Surface six month update (Nov 2009 through April 2010). Field Monitoring and Software Development for Permeable Paving Stormwater Solution Sam Blackbourn, Masters degree, Dept of Civil and Environmental Engineering, University Of Auckland 2006/07. Research into Effective Life of Permeable Pavement Source Control Installations Urban Water Resources Centre Division of IT, Engineering and Enviroment, University of South Australia. Optimisation of the particulate and dissolved matter retention capacity of permeable concrete block paving with infiltration pores by using different material in the infiltration pores Diploma Thesis by P Meyer University of Essen. Field Survey of Permeable Pavement Surface Infiltration Rates by Eban Z Bean, William F Hunt and David A. Bidelspach Journal of Irrigation and Drainage Engineering ASCE. A Guide To Permeable Interlocking Concrete Pavements MA56 November 2010, Concrete Masonry Association of Australia. 13

15 permeable paving firth permeable paving system Te Atatu Peninsula Medical Centre CONCRETE AND MASONRY PRODUCTS: A SUSTAINABLE BUILDING OPTION AND SOLUTION n 4 Manufacturing plants operating in compliance with relevant legislation n 4 All products manufactured according to ISO9001 n 4 Strong focus on reducing transport impacts n 4 Masonry products manufactured according to Lean principles n 4 Greenstar and environmental product options available n 4 Environmental Management Plans operative at all sites n 4 Effective acoustic barrier and fire resistant n 4 Longer and effective building life n 4 Demolished concrete can be recycled, reused or as clean fill n 4 Passive solar heated thermal mass provides energy efficiencies n 4 Highly durable, low maintenance n 4 Rainwater and process water reused in most products For more on Firth s contribution to building a sustainable tomorrow today, visit or call us on for our free brochure. Copyright Firth 2008 Nov 2011 Chalis FIR21259 Available in Available in PRODUCTSPEC